With the advance of LEDs into broad areas of general lighting, there is a great need for simple and inexpensive power supply circuits for these components. There are now a large number of, in particular, integrated circuits which have been designed for such demands. Merely by way of example, the LM3402 chips from the National company and the LT3474 chip from the Linear Technology company may be mentioned in this context. However, such integrated circuits are frequently too expensive for use in mass products. There is therefore a need for the most inexpensive power supply circuit possible for at least one LED.